For this tutorial, I will assume that you have made an 8" square chocolate cake and a single batch recipe of chocolate buttercream and vanilla buttercream (see blog post for recipe links).

Using a long serrated knife or a cake leveller, trim the top off of the cake to make a perfectly flat surface.

Cut the cake in half evenly, and split the halves to make 2 layers for each half of the cake.

Spread a thin layer of frosting between each cake layer to make 2 small rectangle cakes with chocolate frosting between the layers of each.

Cut about 1/3 (or a little more) off of one of the rectangles. This will be the front of the truck.

Gently cut the piece of cake you just separated (the smaller portion) on an angle from about the half-way point on the top to the bottom corner (see picture to understand this step more fully).

Spread a little bit of chocolate frosting on the top of your other rectangle piece of cake. Fasten the larger angled cut piece on top to make the top of the tow truck.

Cut another small slice of cake off of the trimmed piece (about 1" wide, or maybe a little smaller), and fasten one of the two layers onto the back of the head of the truck (see photo).

Set the cake onto a sheet of plastic wrap, and spread a thin layer of chocolate buttecream over the whole surface of the tow truck with a palette knife. Wrap in plastic, and refrigerate until set (at least 1 hour).

While the cake is chilling, make the tow truck hook and its mount. Print my tow truck hook template, and set it onto a cookie sheet with a piece of parchment paper on top.

In a double boiler (or a glass bowl in the microwave for 15 second bursts, stirring between each), melt about 1 cup of melting chocolate until smooth. Spoon the chocolate into a piping bag, and use a pair of scissors to snip off a little hole at the tip. Pipe the shapes on the tow truck template.* Allow to rest in the fridge until completely set, about 10-15 minutes.

Remove the chocolate pieces from the fridge. Stick the 3 triangles together with a bit more melted chocolate (with the short edges attaching to the small triangle in the middle, and the long ends of the larger triangles attaching to each other).

Fasten the two hooks together with melted chocolate, with the flat sides against each other. Set the chocolate pieces aside.

From one batch of vanilla buttercream, you will need:

2 Tbsp white icing

2 Tbsp blue icing

2 Tbsp red icing

(Tint the remainder of the vanilla icing yellow)

From one batch of chocolate buttercream, you will need:

1/4 c. black icing (chocolate buttercream tinted with black gel food coloring)

1/2 c. chocolate icing

Set the chilled cake onto a large serving platter.

Fill a 12-18" piping bag with yellow icing. Cut off the tip, and pipe the icing over the whole surface of the cold truck cake. Use a palette knife to gently spread the icing evenly over the whole surface.

Use the piping bag with chocolate icing to pipe frosting into the back of the truck and over the piece of cake at the back (as pictured).

Use the black chocolate icing to pipe the shapes of the windows, doors, and frame of the truck (as pictured).

Use the white icing to fill in the jagged lines (shine) on the windows (as pictured).

Use the red frosting to pipe lights, the blue for a decorative stripe down the side of the truck, and the white for a license plate. Since my little guy's name is Albert and he turned 2 for this birthday, I piped the license number "A2" on the back of his truck with the black chocolate frosting.

Add yellow M&M's or Rees's Pieces to the truck's lights, front and back.

Gently press the chocolate mount onto the back of the truck, and thread a little string or wire through the top of the mount (you will have to use a toothpick to make a hole for the string). Attach the hook to the string/wire.

IMPORTANT! The #1 rule of cake decorating is that as much as possible of the materials you use should be edible. Since this is a child's birthday cake, if you do use wire (as I did), be sure to remove and discard the wire before any child has access to it as it is not a safe material for them to be handling.

Your fully assembled tow truck cake should be kept at cool room temperature until serving, or in the fridge.

Note: If you keep the cake in the fridge, the chocolate hook may "sweat" (become tacky with condensation) once it comes out, especially in warmer weather.